If you know the day is going to be warm then keep the (sealed) can of polyester resin in the fridge before using. Mix the resin in your favorite Folgers coffee can and set the can in a drain pan filled with ice water. You can get over an hour of working time with the resin this way.

If you have larger areas to do you might want to think about using FabMat instead of mat and cloth. FabMat is a stiched laminate of cloth and mat, comes in quite a few different weights. Cut it to shape dry, wet it out, then carry it to the work area. You can lay down an 1/8" layer in one pass. Great for large flat areas such as floor boards. With the outside layers being cloth the problem of stray strands is virtually eliminated. The stiching keeps the "squirming" of the shape (while being carried) down to a minimum.

Regards, Mark